Sulfur-containing esters of phosphoric acid and methods of preparation



United States Patento F SULFUR-CONTAINING ESTERS OF PHOSPHORIC ACID AND METHODS OF PREPARATION Everett E. Gilbert, Morris Township, Morris County, N.J.,

and Catherine J. McGough, Kew Gardens, N.Y., assignors to Allied Chemical Corporation, a corporation of New York No Drawing. Application November 26, 1956 Serial No. 624,206

6 Claims. (Cl. 260-461) This invention relates to new sulfur-containing esters Patented Jan. 26, 1960 ally, however, the reaction is quite vigorous during the of phosphoric acid useful as insecticidal toxicants and for other purposes and to the preparation of such compounds.

These new sulfur-containing phosphoric acid esters conform to the general formula i i (RO)zPSR-SP(OR')2 g in which R represents an aryl or substituted aryl radical and R' represents an alkyl, substituted alkyl, cycloalkyl or alkenyl radical.

A sulfur-containing phosphoric acid ester of the general formula given above may be prepared according to certain aspects of the invention by reacting an organic phosphite of the general formula in which R has the meaning shown above, with an aromatic disulfonyl chloride of the general formula in which R has the meaning shown above, and recovering said sulfur-containing phosphoric acid esteri The reaction between the organic phosphites and the aromatic disulfonyl chlorides takes place in accordance with the following equation:

' Illustrative of suitable aromatic disulfonyl chlorides are 1-chlorobenzene-2,4-disulfonyl chloride; diphenyloxide-4,4'-disnlfonyl chloride; 1,4-dichlqrobenzene 2,5- disulfonyl chloride; 1-methylbenzene-2,4-disulfonyl chloride; benzene-1,3-disulfonyl chloride; biphenyl-4,4-disulfonyl chloride; dichlorodiphenyloxide-Z,2-disulfonyl chloride; naphthalene-2,7-disulfonyl chloride; diphenylmethane-4,4'-disulfonyl chloride and hexachlorodiphenylmcthane-2,2-disulfonyl chloride. The disulfonyl chlorides may be prepared by any standard procedure such as that given on page 296 in Groggins Unit Processes (4th edition).

Illustrative of suitable organic phosphites are trimethyl, triethyl, tributyl, tri(betachloroethyl), triallyl and tricyclohexyl phosphites. The lower trialkyl phosphites in which the alkyl groups contain 4 or less carbon atoms are preferred reactants, but other phosphites of the general formula given above, including mixed phosphites containing diiferent alkyl, substituted alkyl, cycloalkyl or alkenyl radicals may be effectively employed.

It is preferred that the organic phosphite and aromatic disulfonyl chloride be employed in approximately stoichiometric amounts, i.e. about 6 mols of phosphite for each mol of disulfonyl chloride, to prepare the novel sulfur-containing phosphoric acid esters of the invention. However, higher phosphite-disulfonyl chloride mol ratios are also suitable.

addition of the reactants, and cooling is desirable to retard the reaction. In other cases, gentle warming is required to initiate reaction.

As may be seen from the equation illustrating the reaction of the organic phosphites with the aromatic disulfonyl chlorides, phosphoric acid esters of the general formula in which R has the meaning shown above, are produced during the course of the reaction. These phosphoric acid esters are well known articles of commerce finding usage, for example, as solvents or plasticizers. Since heretofore, these esters have not been produced by such a reaction, their preparation constitutes another feature of our invention. The phosphoric acid esters may be separated from other reaction products by any suitable method such as by vacuum distillation usually at a temperature higher than employed for recovery of preferred lower boiling solvent. We have found, however, that these esters, especially lower trialkyl phosphates are satisfactory inert carriers for the sulfur-containing phosphoric acid esters having active insecticidal properties. In addition, when they are produced in accordance with the invention by reaction of organic phosphites with aromatic disulfonyl chlorides, they are obtained in suflicient quantity that the entire reaction product containing sulfurcontaining ester of phosphoric acid as active insecticidal agent and'phosphoric acid ester as inert carrier may be applied as produced or, diluted, if desired, to the substance to be protected from insects.

The following examples are givenfor the purpose of illustrating the presentinvention, but are not intended to be limiting on the scope thereof.- In the examples parts are by Weight.

Example 1.-10O parts of triethyl phosphite were added dropwise to a'solution of 37.4 parts of l-chloro benzene-2,4-disulfonyl chloride dissolved in 144 parts of ethyl ether, the temperature being maintained below about 30 C. The reaction mixture was allowed to stand at room temperature for several hours and was then heated on a steam bath for 10 hours to complete the reaction. The solution was then vacuum distilled at'3 mm. mercury pressure and heated in an oil bath at 150 C. to remove any remaining ethyl chlorideformed during the reaction and as much-of the ethyl phosphate formed as possible. The product, an oily liquid, comprising the sulfur-containing phosphoric acid ester having the formula (ozHso) IEIS constituted 47 parts 104.5% of theory T Example 2.'37 parts of diphenyloxide-4,4'-disulfofiyl chloride were reacted with parts of triethyl phosphite in accordance with the procedure outlined in Example 1. the sulfur-containing phosphoric acid ester having the The product, a waxy solid, comprising the sulfur-containformula ing phosphoric acid ester producthavingthe formula CH1 u smoognm 1 l (O2Hl0nPs Y i l (Camonfi S fi C2392 constituted 100 parts (86% of theory). 0 Example 10.'100 parts of triethyl phosphite were V reacted with 27.5 parts of benzene-1,3-disulfonyl chloride gigifi; P 3 22 3 fig ig gz 5 di in accordance with the procedure described in Example sulfonyl chloride were reacted with 100 parts of triethyl The F a i i gompnsuig tnthyl PhsPhItte phosphite in accordance with the procedure outlined in and the sulfm-wmammrg phospho-nc acld ester havmg Example 1. The product, a semi-solid, comprisingthe the formula 0 sulfur-containing phosphoric acid ester having the for- H rnula I 1 ?P(OC2H5)1 SP(O 021192 fiwr m (CQH-IOMPST- ll constituted 96 parts (84% of theory). I Example 11.-100 parts of 'triethyl phosphite were tedwith 35.1 parts of biphenyl-4,4,-disulfonyl chloconstituted 61 arts 1267 of theor F As shown ah ove y ields c f Exampl e: 1-3 werein excess nde aig g the mcedure Quill-med Hi 5 1 7 amp e 1 e pro uct, a iquid, comprising trie y fi t fi g y gz g? g'gl gigs due to Incomplete re phosphate andthes'ulfur-containing P osphoric acid ester 1 Examples 4, 5, 6, 7 and 8.In each of these runs the s the m organic phosphite was added dropwise ata temperature of less than 25 C. to a solution of thearomatic disulfonyl chloride in 100 parts of benzene. The mol ratio of organic phosphite to aromatic disulfonyl chloride employed in each run was about 6: 1. After the addition of the organic phosphite was completed, the reaction mixi 01m) ture was allowed to stand at room temperature for 5 0 hours and was then heated overnight on a steam bath to constituted 97 parts (87% of theory) complete the reaction. The resultant solution was then Example 12; parts of methyl phosPhl-te were 2 333 z gg ge gg gg fi zg fig ggi ii reacted with 43.6 parts of dichlorodiphenyloxide 2,2'dif I p S r sulfonyl chloride. The product, a liquid, comprising tria: e V ester, constitute parts" 0 o eory was a liquid Q I P P a m e f Organic phos- Example 13. 100 parts of triethyl phosphite were P t and Sulfur-containing p ph acid ester. reacted with 32.5 parts or naphthalene-2,7-disulfonyl tails of each run are outlined in the table below. chloride in accordance with the procedure outlined 1n Tgtgl Parts Organic Phosphite Parts of Parts of rliosphi t g nd Yield Organic Disulfonyl Chloride Disult'onyl Sulfur-Con- Percent Phosphite Chloride taming Phos- Theory phorie Acid Ester Product lilx.4 trlbutyliu-.. W 75.9 I-chIorobenzene-Zgl-i..-

32 100 Eir.5 -do 75.9 dlphenyloxide-4,4'-... 13.5 35 100 Ex. 6 tri(2-ethy1hexyl) 125.4 benzene-1,13 14 124 .99 Ex. 7 trl(betaehloroethy 81 1-chlorobenzene-2,4- 15,5 36 99 Ex. 8 -do 81 enzene-1,3 14 84 100 Example 9-1 0 pa f rie yl phosphite were Example 9. The product, a liquid, comprising triethyl added dropwise to a solution of 28.9 parts of l-methylphosphate and the sulfur-containing phosphoric acid ester benzene-2,4-disulfonyl chloride in about parts of petrohaving th fo ul leum ether, the temperature being maintained below 0 about 30 C. The reaction mixture was allowed to stand 70 a II it at room temperature for several days to complete the (CHBOMPS- 01m) reaction. The solution was then vacuum distilled to remove any remaining ethyl chloride formed during the reaction and any remaining petroleum ether solvent. The product, a liquid, comprising triethyl phosphate and 15 constituted 99 parts 83% of theory).

Example 14.100 parts of triethyl phosphite were reacted with about 43 parts of diphenylmethane 4,4' disulfonyl chloride in accordance with the procedure outlined in Example 9; The product, a liquid, comprising triethyl phosphate and the sulfur-containing phosphoric acid ester having the formula i (CrHr h fis B nocular constituted 104 parts (85% of theory). Example 15.-About 150 parts of triethyl phosphite were added slowly to a solution of 56 parts of hexachlorodiphenylmethane-2,2'-disulfonyl chloride in 88 parts of benzene. The reaction mixture was allowed to stand at room temperature for several days and was then heated on a steam bath for 8 hours to complete the reaction. The product, a heavy brown liquid, comprising triethyl phosphate and sulfur-containing phosphoric acid ester, constituted 96 parts (67% of theory).

Example 16.-111 parts of trimethyl phosphite were added dropwise with stirring over a period of about /2 SI E CH (CHgO) IIS constituted 53 parts (89.3% of theory).

As indicated above, products of the type produced by this invention find valuable application as active insecticidal toxicants. Insecticidal properties of certain sulfur-containing phosphoric acid esters typical of those embraced within the scope of this invention are indicated .3 6 2 H phoric acid (toxicant), 70% by weight xylene (iiieri solvent) and 5% by Weight Triton X-155. The 12.5% wettable powder used in the tests comprised 12.5% by weight sulfur-containing ester of phosphoric acid (toxicant), 12.5% by weight triethyl phosphate (inert solvent), 73% by weight Attaclay (a commercial attapulgite clay), 1% by weight Nacconol SW (a commercial suspending agent) and 1% by weight Elvanol 4 days.

51-05 (a commercial polyvinyl alcohol dispersing agent). The 25% wettable powder comprised 25% by weight sulfur-containing ester of phosphoric acid (toxicant), 73% by weight Attaclay, 1% by weight Nacconol SW and 1% by weight Elvanol 51-05.

The tests on toxicity to Mexican bean bettle larvae (Epilachna varivestis) were run by dipping cranberry bean plants in the spray mixture, drying the plants and exposing them to the larvae in a spherical wire cage for 3 or The tests on toxicity to mites (Tetranychus'bimaculatus) were run by infesting cranberry bean plants with the mites, dipping the plants in the spray mixture and allowing the plants to stand for 3 or 4 days.

The tests on toxicity to pea aphids (Macrosiphum pisi) were run by placing the pea aphids in an open cage, spraying them with the spray mixture, and then confining the sprayed aphids to young broad-bean plants in a spherical wire cage for 3 days.

Although the above examples are limited to use of aromatic disulfonyl chlorides as reactants, alkyl and substituted alkyl disulfonyl chlorides such as butane disulfonyl chloride and betachloroethyl disulfonyl chloride are also utilizable in the process of this invention.

This application is a continuation-in-part of application Serial No. 397,004, filed December 8, 1953.

We claim:

1. A method of preparing a sulfur-containing phosphoric acid ester of the general formula O (R0),i S-RSii(0R)g in which .R is a member of the group consisting of phenyl, biphenyl, naphthyl, chloro-substituted phenyl, phenoxysubstituted phenyl, chlorophenoxy-substituted phenyl and lower alkyl-substituted phenyl radicals and R is a member of the group consisting of lower alkyl, chloro-substituted lower alkyl, allyl and cyclohexyl radicals, which comprises reacting an organic phosphite of the general formula (RO) P hexyl radicals with an aromatic disulfonyl chloride of the general formula in the following table: c1so R-so,c1

Toxicity to Toxicity to Toxicity to Pea Sulfur-Containing Mexican Bean Mites at Dosage Aphids at Phosphoric Acid Formulation Beetle Larvae Indicated 1 Dosage Indi- Ester fromat Dosage cated Indicated 1 Example 1 25% ernulsible concentrate 100% at Me pt--- 97% at )6: pt Example 2 12.5% ernulsible concentrate 100% at 1 qt Example 3-- do 98% at if; pt..-" Example 9- do 100% at FL... 91% at 9% pt 67% at 1 pt. Example 10 12.5% wettable powder 100% at 82% at 2 lbs. Example 12 12.5% ernulsible concentrate at 34 pt... Example 16 25% wettable powder at l 1b---- 100% at Me lb...

1 Dosage per 100 gallons spray mixture (formulated with water).

The 12.5 ernulsible concentrates used in the above tests comprised 12.5 by weight sulfur-containing ester 70 of phosphoric acid (toxicant), 12.5% by weight triethyl phosphate (inert solvent), 70% by weight xylene (inert solvent) and 5% by weight Triton X-l55 (a commercial emulsifier). The 25% ernulsible concentrate comprised 25% by weight sulfur-containing ester of phosin which R is a member of the group consisting of phenyl, biphenyl, naphthyl, choro-substituted phenyl, phenoxysubstituted phenyl, chlorophenoxy-substituted phenyl and lower alkyl-substituted phenyl radicals, said organic phosphite and aromatic disulfonyl chloride being employed in ratio of at least about 6 mols of organic phosphite to one mol of aromatic disulfonyl chloride.

2. The process of claim 1 in which the organic phosphite and the aromatic disulfonyl chloride are employed in ratio of about 6 mols of organic phosphite to 1 mol of aromatic disulfonyl chloride.' i i 3. The process of. claim 2 in which the reaction is carried out in the presence of an inert solvent.

4. A method of preparing a sulfur-containing phosphoric acid ester of the general formula V t 0 )2i SRSi (OR'), in which R is a member of the group consisting of phenyl, biphenyl, naphthyl, chloro-substituted phenyl, phenoxysubstituted phenyl, chlorophenoxy phenyl and lower alkylsubstituted phenyl radicals and R is a lower alkyl radical,

which comprises reacting an organic phosphite of the general formula in which R is a lower alkyl radical with an aromatic disulfonyl chloride of the general formula in which R is a member of the group consisting of phenyl, biphenyl, naphthyl, chloro-substituted phenyl, phenoxysubstituted phenyl, chlorophenoxy-substituted phenyl and lower alkyl-substituted phenyl radicals, said organic-phosphite and aromatic disulfonyl chloride being employed in ratio of at least about 6 mols of organic phos'phite to one mol of aromatic disulfonyl chloride.

5. A method of preparing the sulfur-containingphosphoric acid ester having the formula ll SP 2 s) a y chlorobenzene-2,4-disulfonyl A method of preparing the sulfur-containing phosphoric acid ester having the formula siqoong,

which comprises reacting trimethyl phosphite with 1- chloride, said reactants being employed in the ratio of about 6 mols of trimethyl phosphite to 1 mol of disulfonyl chloride, in the presence of an inert solvent, and recovering said sulfur-conraining-phosphoric acid ester from the reaction mixture.

References'Cited in the file of this patent v UNITED STATES PATENTS 2,266,514 Romieux et'al. Dec. 16, 1941 2,690,450 Gilbert Sept. 28, 1954 V OTHER REFERENCES Knauer: BerhDeut. Chem, 2125664569 (1894). Mandelbaum; In: Gen. Chem. U.S.S.R., 23, 437-440 (1 953), English translation.

FICE F CORRECTION January 26, 1960 Everett E. Gilbert et al.-

UNITED STAIES PATENT 0F CERTIFICATE 0.

pears in the-printed specification 'quiring correction and that the said Letters d read as correcteii below.

substituted ph-enyl Signed and sealed this 19th day of ."c-hlonophenoxy phenyl" July 1960.

(SEAL) Attest:

KARL AXLINE ROBERT C. WATSON Attesting Ofi'icer Commissioner of Patents 

1. A METHOD OF PREPARING A SULFUR-CONTAINING PHOSPHORIC ACID ESTER OF THE GENERAL FORMULA 